Hi All
We had our bathroom tiled a few years ago. Recently I have
noticed that some of the bottom row of wall tiles - the ones butting up to
the bath - have rung 'hollow' when tapped. Even more recently I noticed that
the grouting between these was failing. So since I have a few days free
(ha!), I have had a closer look. Ended up by pulling of two or three off
this bottom row. They came off pretty easily ;-(.

Underneath there seems to be a thick layer of pink-ish plaster (I don't know
my plaster types very well, sorry) slapped onto the (solid) wall behind.
This plaster is very friable, I easily scratched deep hatch marks into it
with a 50p piece. Images he

http://www.nicorp.co.uk/download/DSCF1856-1.JPG
http://www.nicorp.co.uk/download/DSCF1857-1.JPG

Now I don't know if the plaster is friable because water has got at it, or
it was friable for some reason anyway and that has allowed the tiles to
loosen. It looks like the pink plaster was put on in the first place to
level the wall up - though even with that, the tile adhesive was only
touching it in a few places on each tile, as I think you can see from the
pictures.

I have some spare replacement tiles, and obviously I'm now keen to make this
all good. I'm presuming it would be best to chisel off this rubbish plaster
and replace it (with what?), put on to the right depth so that the
replacement tiles will adhere across their whole surface.

Any other ideas or suggestions?

Thanks a lot
Jon N

The Night Tripper wrote:
Hi All
We had our bathroom tiled a few years ago. Recently I have
noticed that some of the bottom row of wall tiles - the ones butting
up to the bath - have rung 'hollow' when tapped. Even more recently I
noticed that the grouting between these was failing. So since I have
a few days free (ha!), I have had a closer look. Ended up by pulling
of two or three off this bottom row. They came off pretty easily ;-(.

Underneath there seems to be a thick layer of pink-ish plaster (I
don't know my plaster types very well, sorry) slapped onto the
(solid) wall behind. This plaster is very friable, I easily scratched
deep hatch marks into it with a 50p piece. Images he

http://www.nicorp.co.uk/download/DSCF1856-1.JPG
http://www.nicorp.co.uk/download/DSCF1857-1.JPG

Now I don't know if the plaster is friable because water has got at
it, or it was friable for some reason anyway and that has allowed the
tiles to loosen. It looks like the pink plaster was put on in the
first place to level the wall up - though even with that, the tile
adhesive was only touching it in a few places on each tile, as I
think you can see from the pictures.

I have some spare replacement tiles, and obviously I'm now keen to
make this all good. I'm presuming it would be best to chisel off
this rubbish plaster and replace it (with what?), put on to the right
depth so that the replacement tiles will adhere across their whole
surface.

Any other ideas or suggestions?

The pink plaster is skimming and it looks water damaged from those pics.
Either the grout has failed and allowed water ingress or it's an external
downstairs wall?
Possibly penetrating damp if the latter.
Don't try and remove or plaster this patch as you will not be able to get
the tiles right afterwards, simply find the cause of water damage (probably
higher up) and then re-tile and grout

The Night Tripper wrote:

Hi All
We had our bathroom tiled a few years ago. Recently I have
noticed that some of the bottom row of wall tiles - the ones butting up to
the bath - have rung 'hollow' when tapped. Even more recently I noticed
that the grouting between these was failing. So since I have a few days
free (ha!), I have had a closer look. Ended up by pulling of two or three
off this bottom row. They came off pretty easily ;-(.

Underneath there seems to be a thick layer of pink-ish plaster (I don't
know my plaster types very well, sorry) slapped onto the (solid) wall
behind. This plaster is very friable, I easily scratched deep hatch marks
into it with a 50p piece. Images he

http://www.nicorp.co.uk/download/DSCF1856-1.JPG
http://www.nicorp.co.uk/download/DSCF1857-1.JPG

Now I don't know if the plaster is friable because water has got at it, or
it was friable for some reason anyway and that has allowed the tiles to
loosen. It looks like the pink plaster was put on in the first place to
level the wall up - though even with that, the tile adhesive was only
touching it in a few places on each tile, as I think you can see from the
pictures.

I have some spare replacement tiles, and obviously I'm now keen to make
this
all good. I'm presuming it would be best to chisel off this rubbish
plaster and replace it (with what?), put on to the right depth so that the
replacement tiles will adhere across their whole surface.

Any other ideas or suggestions?

Thanks a lot
Jon N

I know it's kind of my default answer, but soak the plaster in 1:2 diluted
SBR a couple of times. It will stabilise it to a few mm depth. The reattach
tiles with fresh adhesive.

I had some polished plaster which BAL instructed (for BAL Green anyway) to
both scrach (wire brush) prime with dilute SBR to stabilse and achieve a
better bond. I had a couple of walls done in one-coat which is softer than
regular gypsum so I primed that too. The result was quite significant - a
mauch harder finish afterwards.

--
Tim Watts

On Sat, 11 Jun 2011 15:12:09 +0100, The Night Tripper wrote:

This plaster is very friable, I easily scratched deep hatch marks into
it with a 50p piece.

Looks more like a base coat to me, that is very soft. If it's sound
I'd not worry too much about it.

TBH it looks a bit of gash tiling job. Why is there a 1/2 strip of
tile above the bath rim? You have two joints just where you don't
want any...

There is signs of water pentration along the bottom of the missing
tiles. Either the silicone has failed or not applied properly or that
grout like above the 1/2" strip has. This would allow damp behind and
would weaken the bond between the tile adhesive and plaster. I expect
all the missing adhesive on the back of the removed tiles.

Think I'd remove the entire bottom row and the silly little strip.
Clean up the tiles and bath rim and refix the tiles with a waterproof
adhesive and water proof grout. I'd also look at removing the grout
between the other tiles at least for the row above inc the horizontal
joint and regrouting with the waterproof grout. When fixing the tiles
back leave a 4mm or so gap above the bath edge(*) and keep that clear
of grout back to the plaster. Once the grout is dry fill the bath to
the overflow with water and fill the gap, full depth, with silicone
sealer. Leave the water in the bath for 24hrs after finishing the
sealing.

The tricky bit will be how far up the adhesive/plaster bond has
failed one may end up with rather more tiles off the wall than on...

(*) If that means having to trim a few mm of that silly strip see if
you can find a decorative strip in a proper tile shop of suitable
width and fix that below the run of tiles that are still on the wall
so the tiles you have off are down next to the bath rim. Depending on
the rest of the tiling and how that relates to other fixtures in the
room doing the above might look naff...

--
Cheers
Dave.